Modern Database Management (12th Edition)
12th Edition
ISBN: 9780133544619
Author: Jeffrey A. Hoffer, Ramesh Venkataraman, Heikki Topi
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 2, Problem 2.34PAE
The Is Married To relationship in Figure 2-12a would seem to have an obvious answer in Problem and Exercise is, until time plays a role in modeling data. Draw a data model for the PERSON entity type and the Is Married TO relationship for each of the following variations by showing the appropriate cardinalities and including, if necessary, any attributes:
- All we need to know is who a person is currently married to, if anyone. (This is likely what you represented in your answer to problem and Exercise 2-33d.)
- We need to know who a person has ever been married to, if anyone.
- We need to know who a person has ever been married to, if anyone, as well as the date of their marriage and the date, if any, of the dissolution of their marriage.
- The same situation as in c, but now assume (which you likely did not do in c) that the same two people can remarry each other after a dissolution of a prior marriage to each other.
- In history, and even in some cultures today, there may be no legal restriction on the number of people to whom one can be currently married. Does your answer to part c of this Problem and Exercise handle this situation or must you make some changes (if so, draw a new ERD).
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
3. Naïve Bayes Models
Describe a classification task from your experience and represent it as a Naïve Bayes model. Make
sure to explicitly specify both the labels and the features. You do not need to specify the values of the
parameters (those would come from data!). To what extent are the independence assumptions made
by a Naïve Bayes model reasonable in your task?
Draw an ER diagram for the following scenario-
• An instructor has an ID, a name, and a phone number. An instructor teaches a course
• A course has a code, course name, credits, and an instructor. Each course uses a textbook.
• A textbook has ISBN, name, publisher, editor, and authors.
Your ER diagram should have entities, attributes, composite attribute, multivalued attribute, key attributes, binary relationships, and a total participation. Explain your rationale behind each design choice.
Please draw the ER diagram on paper showing all seperate parts for each instructor, course and textbook. Showing each connection seperately and explaining which connection is which
ER modeling is one approach in creating a data model. There are several approaches in creating a data model (bottom up, top down, inside out, and mix).
1. explain each of these approaches!2. Then explain when we use top down, bottom up, inside out and mix? what is the function of each of the approaches?
Chapter 2 Solutions
Modern Database Management (12th Edition)
Ch. 2 - Define each of the following terms: entity type...Ch. 2 - Prob. 2.2RQCh. 2 - Contrast the following terms: stored attribute;...Ch. 2 - Prob. 2.4RQCh. 2 - Prob. 2.5RQCh. 2 - Prob. 2.6RQCh. 2 - State six general guidelines for naming data...Ch. 2 - Prob. 2.8RQCh. 2 - Prob. 2.9RQCh. 2 - State three conditions that suggest the designer...
Ch. 2 - List the four types of cardinality constraints,...Ch. 2 - Prob. 2.12RQCh. 2 - What is the degree of a relationship? List the...Ch. 2 - Give an example (Other than those described in...Ch. 2 - Give an example of each of the following, other...Ch. 2 - Give an example of the use of effective (or...Ch. 2 - State a rule that says when to extract an...Ch. 2 - Prob. 2.18RQCh. 2 - In addition to explaining what action is being...Ch. 2 - For the Manages relationship in Figure 2-12a,...Ch. 2 - Explain the distinction between entity type and...Ch. 2 - Why is it recommended that every ternary...Ch. 2 - A cellular operator needs a database to keep track...Ch. 2 - For each of the descriptions below, perform the...Ch. 2 - Answer the following questions concerning Figure...Ch. 2 - Prob. 2.26PAECh. 2 - You may have been assigned a CASE or a drawing...Ch. 2 - Consider the two E-R diagrams in Figure 2-25 Q,...Ch. 2 - The entity type STUDENT has the following...Ch. 2 - Are associative entities also weak entities? Why...Ch. 2 - Because Visio does not explicitly show associative...Ch. 2 - Figure 2-26 shows a grade report that is mailed to...Ch. 2 - Prob. 2.33PAECh. 2 - The Is Married To relationship in Figure 2-12a...Ch. 2 - Prob. 2.35PAECh. 2 - Figure 2-28 shows two diagrams (A and B), both of...Ch. 2 - Prob. 2.37PAECh. 2 - Review Figure 2-8LQ and Figure 2-22. Identify any...Ch. 2 - Prob. 2.39PAECh. 2 - Prob. 2.40PAECh. 2 - Prob. 2.41PAECh. 2 - Prob. 2.42PAECh. 2 - Prob. 2.43PAECh. 2 - Prob. 2.44PAECh. 2 - Prob. 2.45PAECh. 2 - Prob. 2.47PAECh. 2 - Prob. 2.48PAECh. 2 - Draw an ERD for the following situation. (State...Ch. 2 - Prob. 2.50PAECh. 2 - Prob. 2.51PAECh. 2 - Review your answer to Problem and Exercise 2-49 if...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
- There are two alternative methods of representing an employee’s optional (single) phone number. The first is to use a nullable attribute and the second is to use a weak entity. 1. Given a requirement that a large number of the employees (> 80%) are assigned a phone number, which is the preferred method and why? 2. Given a requirement that only a small number of employees (< 10%) are assigned phone numbers, which is the preferred method and why? 3. How would the requirement of ‘multiple phone numbers can be assigned to an Employee’ affect your decision? Your answers should consider the performance tradeoff between number of database operations per query and record’s size.arrow_forwardGive an example of each of the following: a. a supertype/subtype relationship where the disjoint rule applies b. a supertype/ subtype relationship where the overlap rule appliesarrow_forwardConsider an E/R diagram which has information about students, courses, and enrollments, where Students = (Sid, Sname, address, SIN, Program) and Courses = (Cid, Cname, Credits) are the entity sets and Enrollments is a many-to-many re- lationship between them with grade as its own attribute. Give an equivalent E/R diagram (i.e., preserves the information content) in which enrollment is modeled as a weak entity set.arrow_forward
- In the context of EER data modeling, one can represent entities using superclasses and subclasses. Using your own model, explain why one would want to introduce the concepts of superclasses and subclasses into an EER model? I. II. Describe and illustrate using the model in question (I) the process of attribute inheritance. With the model in question (I) describe and contrast the process of specialization with the process of generalization. III. IV. Modify the model to describe the two main constraints that apply to a specialization/generalization relationship.arrow_forwardHow can you tell if a model meets the requirements for proportionality and additivity?arrow_forwardCarry out some study about the positive and negative aspects of using the snowflake and star schemas. Which one is the one that has been normalized a greater amount than the other?arrow_forward
- Data modeling is most often accomplished through the use of a(n) __________________. a. entity-relationship diagram b. data-flow diagram c. functional decomposition diagram d. activity diagramarrow_forwardUsing a graphics program, develop an entity-relationship diagram for a database application for an Internet bookstore where students buy textbooks from a salesperson and receive invoices for their purchases. Use Figure 5.5 as a guide.arrow_forwardThe ______________ model is a simple but highly useful way to organize data into collections of two-dimensional tables called relations.arrow_forward
- OO questions Create the UML diagram for the two entities( person, books). A person has borrowed some books from a library. This can be represented as one to many associations. Please implant this bidirectional association considering that there is no order of the books.arrow_forwardInstead of the snowflake model, write about the pros and cons of the star schema. Which one deviates more?arrow_forwardConsider the differences and similarities between concentration and breadth.There is an instance and a type for each entity.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Information Systems (MindTap Course...Computer ScienceISBN:9781285867168Author:Ralph Stair, George ReynoldsPublisher:Cengage Learning
Database Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781305627482Author:Carlos Coronel, Steven MorrisPublisher:Cengage Learning
Fundamentals of Information SystemsComputer ScienceISBN:9781305082168Author:Ralph Stair, George ReynoldsPublisher:Cengage Learning
Principles of Information Systems (MindTap Course...Computer ScienceISBN:9781305971776Author:Ralph Stair, George ReynoldsPublisher:Cengage Learning
Principles of Information Systems (MindTap Course...
Computer Science
ISBN:9781285867168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781305627482
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Fundamentals of Information Systems
Computer Science
ISBN:9781305082168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Principles of Information Systems (MindTap Course...
Computer Science
ISBN:9781305971776
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Enhanced Entity Relationship Model; Author: Data Science Center;https://www.youtube.com/watch?v=ocQUtXPumdQ;License: Standard YouTube License, CC-BY